Quinoline derivatives having a condensed pyridonecarboxylic acid skeleton and substitution of the 1-position thereof with a cyclopropyl group are known as synthetic antimicrobial agents.
It is further known that 1-cyclopropylquinolone derivatives having a fluorine atom at the 2-position of the cyclopropyl group in a cis-configuration with the pyridonecarboxylic acid moiety also exhibit potent antimicrobial activity, as disclosed in EP-A 341493, which corresponds to JP-A-90-231475 (The terms "EP-A" and "JP-A" as used herein mean an "unexamined published European patent application" and an "unexamined published Japanese patent application", respectively). Said derivatives not only have potent antimicrobial activity but also improved safety.
A variety of antifungal agents have been developed and are in use, see, for example, The Merck Index.